This invention relates to a heat cooking apparatus which heats and cooks a food material in a heating chamber under heat supplied by an electric heater such as an electric oven or a microwave oven with a heater.
The conventional techniques and their problems relating to a heat cooking apparatus are described according to examples as shown in FIGS. 1 to 3.
A cross-sectional view of a conventional heat cooking apparatus is shown in FIG. 1, which illustrates heating chamber 1 comprising upper heater 2, lower heater 3 and pan 4 with food 5 on it to be heated and cooked. Furthermore, FIG. 1 shows magnetron 6 which irradiates microwaves into heating chamber 1 via waveguide 7 to heat food 5; thus the apparatus is an open cooking range employing so-called compound heat of a heater and microwaves.
FIG. 2 is a perspective view of a conventional heater element of a heat cooking apparatus, which is the structure of an openly installed upper heater 2 and lower heater 3 in heating chamber 1. The disadvantage with this structure is that the effective capacity of the heating chamber is reduced because of the volume of the heater, thus resulting in an inconvenience for heating a large-sized article of food. In order to accommodate large-sized food articles, conventional heating chambers must be made larger because of the heater, and consequently, the external dimension of a conventional heating apparatus is made larger requiring a larger space for it to be installed, thus making it inconvenient to use.
Moreover, this kind of heater configuration makes it difficult to clean the inside parts of the heating chamber, e.g. scattered food on the heating chamber wall surface, which also causes this type of conventional heat cooking apparatus to be inconvenient to use.
A conventional-type rod heater makes it difficult to perform uniform heating because the heater applies heat only to the limited area which the heater covers such that the food is thus scorched in the pattern of the heater.
A cross-sectional view of another conventional heat cooking apparatus is shown in FIG. 3, in which the same parts as in FIG. 1 are indicated by the same number and their descriptions thereof are omitted.
In FIG. 3, the upper heater 8 and the lower heater 9 are installed respectively on the outside of the wall of the heating chamber 1, which heats only the heater-contact area of the wall, and accordingly only the heat applied to this area can be conducted into the heating chamber, resulting in that heat conduction efficiency is poorly achieved, resulting in consumption of a great amount of electric power. Such a disadvantage must be avoided from the energy-saving point of view.